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-rw-r--r--fpu/softfloat-parts-addsub.c.inc62
-rw-r--r--fpu/softfloat-parts.c.inc81
-rw-r--r--fpu/softfloat.c253
3 files changed, 255 insertions, 141 deletions
diff --git a/fpu/softfloat-parts-addsub.c.inc b/fpu/softfloat-parts-addsub.c.inc
new file mode 100644
index 0000000000..ae5c1017c5
--- /dev/null
+++ b/fpu/softfloat-parts-addsub.c.inc
@@ -0,0 +1,62 @@
+/*
+ * Floating point arithmetic implementation
+ *
+ * The code in this source file is derived from release 2a of the SoftFloat
+ * IEC/IEEE Floating-point Arithmetic Package. Those parts of the code (and
+ * some later contributions) are provided under that license, as detailed below.
+ * It has subsequently been modified by contributors to the QEMU Project,
+ * so some portions are provided under:
+ * the SoftFloat-2a license
+ * the BSD license
+ * GPL-v2-or-later
+ *
+ * Any future contributions to this file after December 1st 2014 will be
+ * taken to be licensed under the Softfloat-2a license unless specifically
+ * indicated otherwise.
+ */
+
+static void partsN(add_normal)(FloatPartsN *a, FloatPartsN *b)
+{
+ int exp_diff = a->exp - b->exp;
+
+ if (exp_diff > 0) {
+ frac_shrjam(b, exp_diff);
+ } else if (exp_diff < 0) {
+ frac_shrjam(a, -exp_diff);
+ a->exp = b->exp;
+ }
+
+ if (frac_add(a, a, b)) {
+ frac_shrjam(a, 1);
+ a->frac_hi |= DECOMPOSED_IMPLICIT_BIT;
+ a->exp += 1;
+ }
+}
+
+static bool partsN(sub_normal)(FloatPartsN *a, FloatPartsN *b)
+{
+ int exp_diff = a->exp - b->exp;
+ int shift;
+
+ if (exp_diff > 0) {
+ frac_shrjam(b, exp_diff);
+ frac_sub(a, a, b);
+ } else if (exp_diff < 0) {
+ a->exp = b->exp;
+ a->sign ^= 1;
+ frac_shrjam(a, -exp_diff);
+ frac_sub(a, b, a);
+ } else if (frac_sub(a, a, b)) {
+ /* Overflow means that A was less than B. */
+ frac_neg(a);
+ a->sign ^= 1;
+ }
+
+ shift = frac_normalize(a);
+ if (likely(shift < N)) {
+ a->exp -= shift;
+ return true;
+ }
+ a->cls = float_class_zero;
+ return false;
+}
diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc
index efdc724770..cfce9f6421 100644
--- a/fpu/softfloat-parts.c.inc
+++ b/fpu/softfloat-parts.c.inc
@@ -281,3 +281,84 @@ static void partsN(uncanon)(FloatPartsN *p, float_status *s,
p->exp = exp;
float_raise(flags, s);
}
+
+/*
+ * Returns the result of adding or subtracting the values of the
+ * floating-point values `a' and `b'. The operation is performed
+ * according to the IEC/IEEE Standard for Binary Floating-Point
+ * Arithmetic.
+ */
+static FloatPartsN *partsN(addsub)(FloatPartsN *a, FloatPartsN *b,
+ float_status *s, bool subtract)
+{
+ bool b_sign = b->sign ^ subtract;
+ int ab_mask = float_cmask(a->cls) | float_cmask(b->cls);
+
+ if (a->sign != b_sign) {
+ /* Subtraction */
+ if (likely(ab_mask == float_cmask_normal)) {
+ if (parts_sub_normal(a, b)) {
+ return a;
+ }
+ /* Subtract was exact, fall through to set sign. */
+ ab_mask = float_cmask_zero;
+ }
+
+ if (ab_mask == float_cmask_zero) {
+ a->sign = s->float_rounding_mode == float_round_down;
+ return a;
+ }
+
+ if (unlikely(ab_mask & float_cmask_anynan)) {
+ goto p_nan;
+ }
+
+ if (ab_mask & float_cmask_inf) {
+ if (a->cls != float_class_inf) {
+ /* N - Inf */
+ goto return_b;
+ }
+ if (b->cls != float_class_inf) {
+ /* Inf - N */
+ return a;
+ }
+ /* Inf - Inf */
+ float_raise(float_flag_invalid, s);
+ parts_default_nan(a, s);
+ return a;
+ }
+ } else {
+ /* Addition */
+ if (likely(ab_mask == float_cmask_normal)) {
+ parts_add_normal(a, b);
+ return a;
+ }
+
+ if (ab_mask == float_cmask_zero) {
+ return a;
+ }
+
+ if (unlikely(ab_mask & float_cmask_anynan)) {
+ goto p_nan;
+ }
+
+ if (ab_mask & float_cmask_inf) {
+ a->cls = float_class_inf;
+ return a;
+ }
+ }
+
+ if (b->cls == float_class_zero) {
+ g_assert(a->cls == float_class_normal);
+ return a;
+ }
+
+ g_assert(a->cls == float_class_zero);
+ g_assert(b->cls == float_class_normal);
+ return_b:
+ b->sign = b_sign;
+ return b;
+
+ p_nan:
+ return parts_pick_nan(a, b, s);
+}
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 817a91de85..afeef00097 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -749,6 +749,26 @@ static void parts128_uncanon(FloatParts128 *p, float_status *status,
#define parts_uncanon(A, S, F) \
PARTS_GENERIC_64_128(uncanon, A)(A, S, F)
+static void parts64_add_normal(FloatParts64 *a, FloatParts64 *b);
+static void parts128_add_normal(FloatParts128 *a, FloatParts128 *b);
+
+#define parts_add_normal(A, B) \
+ PARTS_GENERIC_64_128(add_normal, A)(A, B)
+
+static bool parts64_sub_normal(FloatParts64 *a, FloatParts64 *b);
+static bool parts128_sub_normal(FloatParts128 *a, FloatParts128 *b);
+
+#define parts_sub_normal(A, B) \
+ PARTS_GENERIC_64_128(sub_normal, A)(A, B)
+
+static FloatParts64 *parts64_addsub(FloatParts64 *a, FloatParts64 *b,
+ float_status *s, bool subtract);
+static FloatParts128 *parts128_addsub(FloatParts128 *a, FloatParts128 *b,
+ float_status *s, bool subtract);
+
+#define parts_addsub(A, B, S, Z) \
+ PARTS_GENERIC_64_128(addsub, A)(A, B, S, Z)
+
/*
* Helper functions for softfloat-parts.c.inc, per-size operations.
*/
@@ -756,6 +776,21 @@ static void parts128_uncanon(FloatParts128 *p, float_status *status,
#define FRAC_GENERIC_64_128(NAME, P) \
QEMU_GENERIC(P, (FloatParts128 *, frac128_##NAME), frac64_##NAME)
+static bool frac64_add(FloatParts64 *r, FloatParts64 *a, FloatParts64 *b)
+{
+ return uadd64_overflow(a->frac, b->frac, &r->frac);
+}
+
+static bool frac128_add(FloatParts128 *r, FloatParts128 *a, FloatParts128 *b)
+{
+ bool c = 0;
+ r->frac_lo = uadd64_carry(a->frac_lo, b->frac_lo, &c);
+ r->frac_hi = uadd64_carry(a->frac_hi, b->frac_hi, &c);
+ return c;
+}
+
+#define frac_add(R, A, B) FRAC_GENERIC_64_128(add, R)(R, A, B)
+
static bool frac64_addi(FloatParts64 *r, FloatParts64 *a, uint64_t c)
{
return uadd64_overflow(a->frac, c, &r->frac);
@@ -824,6 +859,20 @@ static bool frac128_eqz(FloatParts128 *a)
#define frac_eqz(A) FRAC_GENERIC_64_128(eqz, A)(A)
+static void frac64_neg(FloatParts64 *a)
+{
+ a->frac = -a->frac;
+}
+
+static void frac128_neg(FloatParts128 *a)
+{
+ bool c = 0;
+ a->frac_lo = usub64_borrow(0, a->frac_lo, &c);
+ a->frac_hi = usub64_borrow(0, a->frac_hi, &c);
+}
+
+#define frac_neg(A) FRAC_GENERIC_64_128(neg, A)(A)
+
static int frac64_normalize(FloatParts64 *a)
{
if (a->frac) {
@@ -891,18 +940,36 @@ static void frac128_shrjam(FloatParts128 *a, int c)
#define frac_shrjam(A, C) FRAC_GENERIC_64_128(shrjam, A)(A, C)
-#define partsN(NAME) parts64_##NAME
-#define FloatPartsN FloatParts64
+static bool frac64_sub(FloatParts64 *r, FloatParts64 *a, FloatParts64 *b)
+{
+ return usub64_overflow(a->frac, b->frac, &r->frac);
+}
+
+static bool frac128_sub(FloatParts128 *r, FloatParts128 *a, FloatParts128 *b)
+{
+ bool c = 0;
+ r->frac_lo = usub64_borrow(a->frac_lo, b->frac_lo, &c);
+ r->frac_hi = usub64_borrow(a->frac_hi, b->frac_hi, &c);
+ return c;
+}
+#define frac_sub(R, A, B) FRAC_GENERIC_64_128(sub, R)(R, A, B)
+
+#define partsN(NAME) glue(glue(glue(parts,N),_),NAME)
+#define FloatPartsN glue(FloatParts,N)
+
+#define N 64
+
+#include "softfloat-parts-addsub.c.inc"
#include "softfloat-parts.c.inc"
-#undef partsN
-#undef FloatPartsN
-#define partsN(NAME) parts128_##NAME
-#define FloatPartsN FloatParts128
+#undef N
+#define N 128
+#include "softfloat-parts-addsub.c.inc"
#include "softfloat-parts.c.inc"
+#undef N
#undef partsN
#undef FloatPartsN
@@ -980,165 +1047,73 @@ static float64 float64_round_pack_canonical(FloatParts64 *p,
}
/*
- * Returns the result of adding or subtracting the values of the
- * floating-point values `a' and `b'. The operation is performed
- * according to the IEC/IEEE Standard for Binary Floating-Point
- * Arithmetic.
- */
-
-static FloatParts64 addsub_floats(FloatParts64 a, FloatParts64 b, bool subtract,
- float_status *s)
-{
- bool a_sign = a.sign;
- bool b_sign = b.sign ^ subtract;
-
- if (a_sign != b_sign) {
- /* Subtraction */
-
- if (a.cls == float_class_normal && b.cls == float_class_normal) {
- if (a.exp > b.exp || (a.exp == b.exp && a.frac >= b.frac)) {
- shift64RightJamming(b.frac, a.exp - b.exp, &b.frac);
- a.frac = a.frac - b.frac;
- } else {
- shift64RightJamming(a.frac, b.exp - a.exp, &a.frac);
- a.frac = b.frac - a.frac;
- a.exp = b.exp;
- a_sign ^= 1;
- }
-
- if (a.frac == 0) {
- a.cls = float_class_zero;
- a.sign = s->float_rounding_mode == float_round_down;
- } else {
- int shift = clz64(a.frac);
- a.frac = a.frac << shift;
- a.exp = a.exp - shift;
- a.sign = a_sign;
- }
- return a;
- }
- if (is_nan(a.cls) || is_nan(b.cls)) {
- return *parts_pick_nan(&a, &b, s);
- }
- if (a.cls == float_class_inf) {
- if (b.cls == float_class_inf) {
- float_raise(float_flag_invalid, s);
- parts_default_nan(&a, s);
- }
- return a;
- }
- if (a.cls == float_class_zero && b.cls == float_class_zero) {
- a.sign = s->float_rounding_mode == float_round_down;
- return a;
- }
- if (a.cls == float_class_zero || b.cls == float_class_inf) {
- b.sign = a_sign ^ 1;
- return b;
- }
- if (b.cls == float_class_zero) {
- return a;
- }
- } else {
- /* Addition */
- if (a.cls == float_class_normal && b.cls == float_class_normal) {
- if (a.exp > b.exp) {
- shift64RightJamming(b.frac, a.exp - b.exp, &b.frac);
- } else if (a.exp < b.exp) {
- shift64RightJamming(a.frac, b.exp - a.exp, &a.frac);
- a.exp = b.exp;
- }
-
- if (uadd64_overflow(a.frac, b.frac, &a.frac)) {
- shift64RightJamming(a.frac, 1, &a.frac);
- a.frac |= DECOMPOSED_IMPLICIT_BIT;
- a.exp += 1;
- }
- return a;
- }
- if (is_nan(a.cls) || is_nan(b.cls)) {
- return *parts_pick_nan(&a, &b, s);
- }
- if (a.cls == float_class_inf || b.cls == float_class_zero) {
- return a;
- }
- if (b.cls == float_class_inf || a.cls == float_class_zero) {
- b.sign = b_sign;
- return b;
- }
- }
- g_assert_not_reached();
-}
-
-/*
- * Returns the result of adding or subtracting the floating-point
- * values `a' and `b'. The operation is performed according to the
- * IEC/IEEE Standard for Binary Floating-Point Arithmetic.
+ * Addition and subtraction
*/
-float16 QEMU_FLATTEN float16_add(float16 a, float16 b, float_status *status)
+static float16 QEMU_FLATTEN
+float16_addsub(float16 a, float16 b, float_status *status, bool subtract)
{
- FloatParts64 pa, pb, pr;
+ FloatParts64 pa, pb, *pr;
float16_unpack_canonical(&pa, a, status);
float16_unpack_canonical(&pb, b, status);
- pr = addsub_floats(pa, pb, false, status);
+ pr = parts_addsub(&pa, &pb, status, subtract);
- return float16_round_pack_canonical(&pr, status);
+ return float16_round_pack_canonical(pr, status);
}
-float16 QEMU_FLATTEN float16_sub(float16 a, float16 b, float_status *status)
+float16 float16_add(float16 a, float16 b, float_status *status)
{
- FloatParts64 pa, pb, pr;
-
- float16_unpack_canonical(&pa, a, status);
- float16_unpack_canonical(&pb, b, status);
- pr = addsub_floats(pa, pb, true, status);
+ return float16_addsub(a, b, status, false);
+}
- return float16_round_pack_canonical(&pr, status);
+float16 float16_sub(float16 a, float16 b, float_status *status)
+{
+ return float16_addsub(a, b, status, true);
}
static float32 QEMU_SOFTFLOAT_ATTR
-soft_f32_addsub(float32 a, float32 b, bool subtract, float_status *status)
+soft_f32_addsub(float32 a, float32 b, float_status *status, bool subtract)
{
- FloatParts64 pa, pb, pr;
+ FloatParts64 pa, pb, *pr;
float32_unpack_canonical(&pa, a, status);
float32_unpack_canonical(&pb, b, status);
- pr = addsub_floats(pa, pb, subtract, status);
+ pr = parts_addsub(&pa, &pb, status, subtract);
- return float32_round_pack_canonical(&pr, status);
+ return float32_round_pack_canonical(pr, status);
}
-static inline float32 soft_f32_add(float32 a, float32 b, float_status *status)
+static float32 soft_f32_add(float32 a, float32 b, float_status *status)
{
- return soft_f32_addsub(a, b, false, status);
+ return soft_f32_addsub(a, b, status, false);
}
-static inline float32 soft_f32_sub(float32 a, float32 b, float_status *status)
+static float32 soft_f32_sub(float32 a, float32 b, float_status *status)
{
- return soft_f32_addsub(a, b, true, status);
+ return soft_f32_addsub(a, b, status, true);
}
static float64 QEMU_SOFTFLOAT_ATTR
-soft_f64_addsub(float64 a, float64 b, bool subtract, float_status *status)
+soft_f64_addsub(float64 a, float64 b, float_status *status, bool subtract)
{
- FloatParts64 pa, pb, pr;
+ FloatParts64 pa, pb, *pr;
float64_unpack_canonical(&pa, a, status);
float64_unpack_canonical(&pb, b, status);
- pr = addsub_floats(pa, pb, subtract, status);
+ pr = parts_addsub(&pa, &pb, status, subtract);
- return float64_round_pack_canonical(&pr, status);
+ return float64_round_pack_canonical(pr, status);
}
-static inline float64 soft_f64_add(float64 a, float64 b, float_status *status)
+static float64 soft_f64_add(float64 a, float64 b, float_status *status)
{
- return soft_f64_addsub(a, b, false, status);
+ return soft_f64_addsub(a, b, status, false);
}
-static inline float64 soft_f64_sub(float64 a, float64 b, float_status *status)
+static float64 soft_f64_sub(float64 a, float64 b, float_status *status)
{
- return soft_f64_addsub(a, b, true, status);
+ return soft_f64_addsub(a, b, status, true);
}
static float hard_f32_add(float a, float b)
@@ -1216,30 +1191,26 @@ float64_sub(float64 a, float64 b, float_status *s)
return float64_addsub(a, b, s, hard_f64_sub, soft_f64_sub);
}
-/*
- * Returns the result of adding or subtracting the bfloat16
- * values `a' and `b'.
- */
-bfloat16 QEMU_FLATTEN bfloat16_add(bfloat16 a, bfloat16 b, float_status *status)
+static bfloat16 QEMU_FLATTEN
+bfloat16_addsub(bfloat16 a, bfloat16 b, float_status *status, bool subtract)
{
- FloatParts64 pa, pb, pr;
+ FloatParts64 pa, pb, *pr;
bfloat16_unpack_canonical(&pa, a, status);
bfloat16_unpack_canonical(&pb, b, status);
- pr = addsub_floats(pa, pb, false, status);
+ pr = parts_addsub(&pa, &pb, status, subtract);
- return bfloat16_round_pack_canonical(&pr, status);
+ return bfloat16_round_pack_canonical(pr, status);
}
-bfloat16 QEMU_FLATTEN bfloat16_sub(bfloat16 a, bfloat16 b, float_status *status)
+bfloat16 bfloat16_add(bfloat16 a, bfloat16 b, float_status *status)
{
- FloatParts64 pa, pb, pr;
-
- bfloat16_unpack_canonical(&pa, a, status);
- bfloat16_unpack_canonical(&pb, b, status);
- pr = addsub_floats(pa, pb, true, status);
+ return bfloat16_addsub(a, b, status, false);
+}
- return bfloat16_round_pack_canonical(&pr, status);
+bfloat16 bfloat16_sub(bfloat16 a, bfloat16 b, float_status *status)
+{
+ return bfloat16_addsub(a, b, status, true);
}
/*
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-01 23:08:20 +0000